Saving the Oysters

June 16, 1991

Is it time to clamp a moratorium on oystering in the Chesapeake Bay? The Chesapeake Bay Foundation's landmark report, "Turning the Tide: Saving the Chesapeake Bay" makes a persuasive case, noting that oysters have declined to 1 percent of their former abundance. Those bivalves, enough to fill 12 million bushels during the 1870s, once sifted all the bay's waters in a week, but now take nearly a year. What that does to water quality is a life-and-death matter for many plant and animal species depending on the bay.

The report's author, former Sun environmental writer Tom Horton, joined other foundation members in demanding a three-year ban on oystering, similar to the ban on rockfish catches, to help bring back the threatened population.

Torrey C. Brown, secretary of the Maryland Department of Natural Resources, disagrees. Dr. Brown, charged with protecting bay habitats and species but also concerned with the livelihoods of up to 3,000 oystermen, notes that finfish bans protect migratory species which move thousands of miles in a year. Halting the harvest at the point of spawning boosts such populations relatively easily.

But -- here's the point -- oysters do not migrate.

The Chesapeake already holds 200,000 acres of sanctuary, Dr. Brown observes, but bivalve populations there are not increasing. Owing to the ravages of disease, silting and reduced oxygen in the water, annual "spat sets" -- attachment of larvae to hard surfaces -- have remained stable.

That argues for other solutions. No one knows what causes MSX, the disease devastating Maryland's oyster beds, but it is known that it propagates better in salty water than fresh water. Natural Resources personnel have even found that yearling oysters known to be infected with the disease can be moved from areas near Crisfield to the mouth of the Choptank River, where their health improves and they grow to adulthood. Another recent idea, cleaning old oyster shells and depositing them in spawning areas just as the free-swimming larvae are ready to "spat" results in dramatic boosts in harvests, Dr. Brown says.

Thus, Department of Natural Resources staffers are looking at ways to rebuild the oyster's habitat. They'd like to strip old, long-extinct oyster beds in the bay's north, clean and redeposit the shells lower in the bay. Dr. Brown thinks that if an affordable method can be found, this holds better long-term hope for the oysters and their harvesters.

Something will have to be done quickly. Silting continues from farming, shoreline construction and powerplant expansion as more and more people join the 15 million now living in the 64,000-square-mile Chesapeake Bay watershed. Waiting several more years to save the oysters and the tradition-rich oyster industry is a non-starter. Bay life cannot be allowed to become a non-finisher.